This invention relates to a novel process for preparing (2S, 3R)-3-phenylglycidic acid esters.
(2S, 3R)-3-phenylglycidic acid esters are important compounds as synthetic intermediates of 1,5-benzothiazepine derivatives (U.S. Pat. No. 4,590,188) having coronary blood vessel vasodilating activity or platelet aggregation-inhibiting activity, and other various pharmaceutical compounds. In the prior art, as the method for preparing such a (2S, 3R) type compound, there has been known the method in which a racemic mixture of methyl trans-3-(4methoxyphenyl)glycidate is hydrolyzed to form a corresponding carboxylic acid, which carboxylic acid is optically resolved with an optically active amine and then esterified to give methyl (2S, 3R)-3-(4-methoxyphenyl)glycidate (Chemical Abstract, 103, 71179w and 71180q (1985)).
However, the above-mentioned method has many steps, and also there was involved the drawback that the product of the optically active methyl 3-(4-methoxyphenyl)glycidate could be obtained only as an oily product with low purity.